In general, rotary covers for opening and closing pianos, notebook computers, and office appliance, such as copy machines, and opening-and-closing covers of refrigerated compartments for reagents and analyzers, such as DNA analyzers and antibody detectors, are provided such that one end of the cover is supported by a rotary shaft and the other end is rotatable in the vertical direction.
However, when the above-described type of covers is to be closed, the weight of the cover itself is exerted in the closing direction, causing the cover to tend to slam shut. When the cover is slammed shut, the cover and the main body may be damaged by the shock from closing the cover. In particular, a heavy cover tends to slam shut, causing damage, namely, breaking the cover.
Accordingly, to prevent such damage, various techniques have been proposed to prevent the cover from slamming shut (for example, refer to Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Application, Publication No. HEI-8-46369 (p. 3, FIG. 1)